0.6CaxSr1-xTiO3-0.4LaAlO3(x=0.6~0.9)微波介电陶瓷的微观结构及介电性能研究

Microstructure and Microwave Dielectric Properties of 0.6CaxSr1-xTiO3-0.4LaAlO3(x=0.6~0.9)Microwave Dielectric Ceramics

采用固相反应法制备0.6CaxSr1-xTiO3-0.4LaAlO3(x=0.6~0.9)微波介质陶瓷,通过DSC确定了CaxSr1-xTiO3(x=0.6~0.9)和LaAlO 3的预烧温度,结果表明在1150℃保温4 h可得到纯CaxSr1-xTiO3相,在1250℃[JP2]保温4 h可得到纯LaAlO3相,将CaxSr1-xTiO3与LaAlO3按化学计量式0.6CaxSr1-xTiO3-0.4LaAlO3(x=[JP]0.6~0.9)称料并二次球磨,在1400℃、1450℃、1500℃下进行煅烧。通过XRD、白光干涉仪和矢量网络分析仪研究了四组陶瓷样品的微观组织形貌和介电性能,其结果显示:当0.6CaxSr1-xTiO3-0.4LaAlO3(x=0.90)时,烧结温度为1450℃并保温4 h可以制备出烧结致密,结构均一的单相陶瓷样品,并展示出优异的介电性能;εr=40,Q×f=25295 GHz,τf=16 ppm/℃。

0.6CaxSr1-xTiO3-0.4LaAlO3(x=0.6~0.9)microwave dielectric ceramics were prepared by solid-phase reaction.The calcination temperatures of CaxSr1-xTiO3(x=0.6~0.9)and LaAlO3 were determined by DSC.The results show that pure Ca x Sr 1-x TiO 3 phase can be obtained by holding at 1150℃for 4 h,and pure LaAlO3 phase can be obtained by holding at 1250℃for 4 h.The calcined powders were re-milled according to stoichiometry 0.6CaxSr1-xTiO3-0.4LaAlO3(x=0.6~0.9)and sintered at 1400℃、1450℃、1500℃respectively.The microstructure and dielectric properties of four groups of ceramic samples were studied by XRD Profile and vector network analyzer respectively.The results show that when 0.6CaxSr1-xTiO3-0.4LaAlO3(x=0.9),the sintering temperature is 1450℃and holding for 4 h can prepare sintered compact uniform structure single-phase ceramic samples.And showed excellent dielectric properties:εr=40,Q×f=25295 GHz,τf=16 ppm/℃.